Measurements of the HONO photodissociation constant     

K. J. Wall  C. L. Schiller  G. W. Harris 《Journal of Atmospheric Chemistry》2006,55(1):31-54

Measurements of the photodissociation constant for nitrous acid (j _HONO) were made at an urban site in Toronto, Canada, during the months of May–July 2005, using an optically thin actinometer. Operating details of the j _HONO monitor are reported, along with laboratory tests. Measurements of j _HONO were obtained for solar zenith angles ranging from 20–75^∘, under clear and cloudy skies. Maximum error estimates on j _HONO under clear skies range from 11% at sunrise, to 4% at solar noon, with a minimum detection limit of 5.7 × 10⁻⁴/sec for our actinometer. Measured clear-sky values of j _HONO were compared with values calculated by a four-stream discrete ordinate radiative transfer (RT) model (ACD TUV version 4.1), and were found to be within better than 10% agreement for solar zenith angles < 65^∘. For conditions of scattered cloud, enhancement and suppression of the j _HONO values occurred by as much as 16%–70%, and 59%–80%, respectively. The integrated band area of the nπ^∗ transition for gas-phase nitrous acid yields an oscillator strength, f = (1.06 ± 0.044)×10⁻³ (based on clear-sky data), 19.1% higher than the value reported by Bongartz et al. (1991).  相似文献   

Chemical “light meters” for photochemical and photobiological studies     

David J. Kieber  Dierdre A. Toole  Joseph J. Jankowski  Ronald P. Kiene  George R. Westby  Daniela A. del Valle  Doris Slezak 《Aquatic Sciences - Research Across Boundaries》2007,69(3):360-376

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